1. Field of the Invention
The present invention relates, inter alia, to a device for fitting to a vehicular snorkel air intake, and a forward facing vehicular snorkel air intake.
2. Description of Related Art
To provide a constant air flow into the engine, regardless of speed, most car manufacturers build engines with air intakes that face forward in the car's engine bay or inner guard, as close to the grille as possible. Having the air intake in this location is convenient during travel on well maintained roads, where undesirable contaminants such as dust particles, sand and water are unlikely to enter the air intake and cause engine damage or clog the air filter.
However, engine air intakes located near the road often cause problems for drivers that take their vehicles (e.g. four wheel drives) off-road or onto less travelled roads as this tends to involve driving on dusty roads, sandy beaches, and/or through rivers and creeks. If the vehicle travels through a significant amount of water, the air inlet can be filled with water and inhibit air flow through the air filter causing the vehicle to stall. If the engine vacuum becomes high enough, water may be sucked into the engine and damage the engine. Inside the combustion chamber, when water is rapidly heated during the combustion process it turns instantly to steam resulting in a dramatic increase in combustion cylinder pressure. If excessive water is sucked in, then the water will not turn to steam. This can cause instant engine damage, particularly in diesel and turbo diesel engines as they cannot tolerate any water intake due to the high compression pressures required for a diesel to operate. Although petrol engines can tolerate small amounts of water, excess amounts of water will damage internal engine components.
Thus, to minimise dust, sand and water intake, and ensure that a supply of cleaner, dry air is available regardless of road conditions, many drivers have an external snorkel with an elevated air intake fitted to their vehicles. The snorkel is typically in the shape of a tube that contours its way from the air filter inlet, along one of the front wings and up beside the “A” pillar to the level of the roofline where it is terminated with an air intake (most air intakes are forward facing). The snorkel raises the effective height of the engine air intake up to the roof level of the vehicle.
Due to the extra height of the engine air intake, river and/or flood water is less likely to enter the engine air system. Furthermore, less dust and/or sand particles are being picked up and held in the air filter, resulting in a longer air filter life. Moreover, a cooler charge of air due to the increased distance away from the hot road surface and away from the hot engine bay, results in more energy. This cooler air charge increases the power the engine produces, therefore less throttle is required resulting in better fuel economy.
Although snorkels may mitigate some of the problems associated with a low set engine air intake in challenging driving conditions, snorkels are associated with other problems such as vast changes in air intake volume and air pressure, relative to vehicle speed.
Another problem with snorkels is their high level of rain intake during periods of rain. If the volume of water saturates the air filter, engine vacuum will draw any excess water through the filter and into the combustion chamber, resulting in detrimental outcomes ranging from poor engine performance to engine damage (diesel engines are particularly prone to damage from water ingestion).
Yet another problem with snorkels is that vehicles that are dual fuel vehicles, e.g. petrol and LPG running on liquid petroleum gas (LPG) need modifications to the air filter system to stop air ram pressure causing the engine to stall after lifting off the throttle. One of the ways to overcome issues relating to a forward facing snorkel head with a vehicle running on LPG (such as the air ramming effect) is to turn the snorkel head to the rear of the vehicle. However, the higher the vehicle speed the lower the pressure in the snorkel and air intake system, (as the fresh air is now passing the rear facing snorkel air intake), resulting in higher, less economic, fuel consumption.
It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.